I want a lower voltage but higher RPM motor. I am planning on building a 2 wheel drive robot and i want it to move relatively fast. I am estimating the robot to weigh no more than 10-15 LBS so to be on the safe side I want a motor that can EASILY move 20 LBS of robot. Any ideas? Again this is just a mental concept so i can start pricing the total build, thank you,

1. How much do you want to spend. (price vs performance) 2. What is fast. Walking speed, running?3. Do you need a wheel kit? Or just the motors? 4. Incline? 5. What battery are you using and how long do you need the robot to drive? 6. Are you using treads? 7. Do you need encoders?

We need more info. But in the mean time here are some wheel/motor kits.

This is a good source, http://www.robotmarketplace.com/products/battlekit_drive_modules.htmlMore motors here: http://www.robotmarketplace.com/products/motors_geared.html

You will need something in the 2-3" motor diameter range, along the lines of something that is twice as powerful as a battery drill motor (10-20 amps). More in line with higher performance motorized skateboards. http://www.zboardshop.com/

Remember that everything on Craigslist is roughly %40 off the original price.

For a robot of 20lbs or so you will need to address the high current load on the motors by making sure your speed control is hearty. You can experiment with cheaper controllers and just upgrade once they burn out. The supper duty controllers are either wheel chair controllers or some of these. http://www.robotmarketplace.com/products/speed_controllers_main.html

Thank you everyone for your responses. I want the robot to move about running speed and be able to run for at least an hour. I don't want to spend more than about $75 for the pair of motors. I will be using wheels, not treads. I have never used an encoder before so im not sure whether I want or need one honestly. If you have a good wheel kit with motors in my price range by all means I would love to have a wheel kit! Thank you again for all of the links and help!!

Ok so I checked around and this motor is with in you budget and it should work…http://www.robotshop.com/solutions-cubed-easy-roller-robot-wheel-ezr2-1.html?lang=en-us

And if you use this battery….http://www.all-battery.com/sidebyside12v4200mahexpandablenimhbatterypackmodules.aspx

And this motor driver…http://www.robotshop.com/productinfo.aspx?pc=RB-Dfr-19&lang=en-US

You SHOULD be able to drive your robot around for about an hour. The acceptation would be if your going up hills or what not. Then you will not have as long as run time.

It seems like it would go fast, but I'm not sure how to do the calculations so somebody else will have to comment on that. This is probably the best motor for your price range. If you want more speed/torque your going to need to go up to $75-$100 per motor.